The technique of a contents base router and a contents based network is disclosed in Patent Literature 1 (JP 2006-203904A). In this technique, it is checked whether or not the contents of a data packet and a stored subscription match in an entrance router. When matching to each other, a routing label showing an exit router corresponding to a subscriber of the matched subscription is assigned to the data packet, and the data packet is transmitted to contents based router as a destination. It should be noted that the subscriber shows a user who subscribes to the contents. Also, the subscription shows query data and selection condition which the subscriber prescribes.
In the technique disclosed in Patent Literature 1, the contents data described in meta language called XML (Extensible Markup Language) and subscription data described in XML are made match to each other and a delivery destination is determined.
As a method of realizing the contents based router, there are a method of determining processing in each XML router while the router on a route compares an XML description with an XML query, and a method of adding a label to a packet after determining the destination of the contents and then of carrying out routing based on the label, as in Patent Literature 1.
As processing similar to the routing processing in the contents based router, there is a case that the processing to determine a destination based on message contents of the communication data is carried out. For example, in a load balancer, the processing is carried out to select a destination server based on an identifier contained in a HTTP header called Cookie and URI (Unified Resource Identifier) used in HTTP (Hyper Text Transfer Protocol). However, although the destination server can be selected based on the contents of URI and Cookie, the route cannot be specified by this processing.
In the above-mentioned load balancer, an optimal destination can be selected by applying a policy to URI and a value of Cookie which are contained in a request message of HTTP. Thus, in case of HTTP communication, the server which provides service can be selected. However, even if the optimal server can be selected, it is not possible to specify a network path, because the route to the server follows TCP/IP (Transmission Control Protocol/Internet Protocol). Also, it is not possible to specify a band to be assigned in addition to the network path. Therefore, it is difficult to transfer to specific URI by using the circuit of the broadband.
To realize this, it is necessary that an destination server is determine with URI and Cookie and the routing control is carried out in consideration of QoS (Quality of Service) when being connected with the destination server after the destination server is determined. However, in this case, the policy specification is necessary in each of 2 types of processing of processing of determining a destination server by use of the URI and Cookie, and processing of determining a network path used for the connection to the destination server.
On the other hand, in the contents based network processing shown in Patent Literature 1, a label is assigned to a packet based on the contents and relay processing on the network is carried out based on the label. Therefore, it is possible to specify an optimal route and relay the packet by the contents base router specifying a transfer policy to a label switch when assigning the label to the packet according to the contents.
However, a relay unit called the label switch is required to interpret the label in the transfer processing using the label. The label switch interprets the label and carries out the switching processing based on the label.
Also, in case of using TCP which has reliability, as a transport protocol to deliver the contents, two types of processing are needed of the processing of establishing a TCP connection to an exit router corresponding to a subscriber of a subscription and the processing of specifying a label and transferring the packet. Because a TCP/IP header is added to the packet for the transfer using a TCP connection, it is desired that the transfer processing is carried out on the packet of a TCP/IP form as it is without addition of a label to the header.
As the related technique, Patent Literature 2 (JP 2004-304456A) discloses a technique related to a network management apparatus and a network apparatus which are used for a network system, a method and same system of setting a path. In this technique, the network management apparatus calculates and determines a transfer route which satisfies a specific reference to the contents provided between network apparatuses periodically or at the time of occurrence of a predetermined event. Also, this network management apparatus generates a correspondence table in which the specific contents are related to the calculated transfer route which is optimal to transmission of the contents, and transmits a request message to the network apparatus (edge router) from the correspondence table according to the requested contents by the user. When receiving the request message, the network apparatus (edge router) extracts a passage node list in the concerned message, and sets (establishes) MPLS (Multi-Protocol Label Switching) path by using a predetermined path set signaling (path set message) based on the passage node list.
Also, Patent Literature 3 (JP 2007-096741A) discloses a technique that is related to a port hopping detecting system, a band control system, a port hopping detecting method and a program. In this technique, the port hopping flow detecting apparatus calculates data of the port hopping of a plurality of received flows and detects the port hopping by comparing the calculation result and application data.